Saturday, January 31

It is hard to argue against the fact that so-called “natural” selection has at least significantly slowed, if not come close to a complete halt. All one has to do is look at infant mortality rates today compared to even a few generations ago, let alone a few hundred years ago. Today, people with genetic disorders and/or weak immune systems due to heritable factors, can live to maturity - giving them essentially the same odds of reproducing as individuals with superior genes. Furthermore, another “natural” force driving evolutionary change in "natural populations – adaptations to different geographical environments, or niches – has been effectively negated by recent inventions, i.e. planes, trains, and automobiles. The reason increased mobility negatively effects the rate and quantity of change is that for rare adaptations - such as those that arise in small populations as a result of a niche environment - to persist and become prominent, there must be reproductive isolation. Otherwise, genes that are beneficial only in a niche environment will be diluted out by more prominent genes from immigrants, or lost due to migration of individuals who inherit said genes. In other words, THE DAYS OF “NATURAL” FORCES/PREDATORS SHAPING OUR EVOLUTION ARE ESSENTIALLY OVER.

The article (click the picture, title of the post, or here for the link) discusses the forces driving human evolution today, and some of the possible outcomes. What Ward claims, and I agree, is that THE STRONGEST DRIVING FORCE IN OUR EVOLUTION TODAY IS CULTURE. Meaning the strongest factor affecting what evolutionary biologists define as “fitness” – or the ability to reproduce – is the ability to “fit in.” This doesn’t necessarily mean being cool, but rather being able to find your niche in a particular society or culture. Some people may argue that human behaviors/personalities are not inherited - and therefore cannot influence evolution. However, there is increasing evidence that at least certain behavioral traits – ADHD for example, or tendency towards alcoholism and addiction – are in fact highly heritable traits.

While certainly not all behavioral traits are simply inherited (and therefore highly heritable), and those that are simply inherited are influenced by other factors like random chance and environmental factors, it is my belief that future discoveries will reveal that a significant portion of personality is in fact heritable. Psychologist Eric Turkheimer is quoted in the article “My Genome, My Self,” by Steven Pinker (discussed in the previous post), going as far as to say that,

THE NATURE-NURTURE DEBATE IS OVER… ALL HUMAN BEHAVIORAL TRAITS ARE HERITABLE.

When it comes to the future, Ward discusses two possible scenarios, both quite science-fiction in nature, but both rational possibilities. One is the infamous artificial intelligence (AI) scenario, in which we create robots with the ability to think for themselves, which then leads to the (inevitable?) ironic ending in which the machines we create, and ultimately come to depend on for survival, end up taking over. All I can say about the AI scenario is: I like to watch movies about the topic. But I certainly don’t have the expertise to speculate about the acumen of any arguments for, or against, the possibility.

The second scenario involves genetic modification, a topic with which I am much more familiar. But before I start , I want to preface my comments by saying that the proceeding concepts (along with AI) are still not feasible, and probably won’t be for quite some time (see previous post).

Now, genetic modification can be broken down into two categories: somatic cell modification (or gene therapy as it is often called) and germ-cell “therapy”. Somatic cell modification will absolutely be a reality at some point in the future, and probably far before germ-cell modification. And when it comes to somatic cell therapy, I personally have no objections (at this point – though I reserve my right to change my opinion – but I certainly have no “moral” objections to the concept). I’m sure, however, that when the possibility does become a reality it will be a hot topic for debate - as there will surely be plenty who feel strongly against it, just as there are many against genetically modified plants now.

When it comes to germ-cell genetic modification, all I really want to say is that, even when our great, great, great…grandchildren have a much better understanding of the human genome, I hope they are smart enough not to mess with germ-cells. What’s to keep every couple expecting a child to have the DNA analyzed to find what to fix. And if you ask me, that scenario can only play out to one end: everyone will be beautiful and intelligent, with an agreeable disposition – after all, WHO WOULD CHOOSE FOR THEIR KID TO BE UGLY AND STUPID?!? That's not to say the human race would turn into a completely homogenous group of “clones,” but it would be a very real possibility - and that’s one of the more benign forecasts when it comes to the possible consequences of messing with germ-cells.

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ABOUT THE BLOG

This blog is written by me, a 26 year old plant biology and genetics student at Cornell University (who happens to be looking for a job: click for info). It is (among other things) an attempt to make science both interesting and accessible, as well as to convey the relevance of science in an everyday context - i.e. the direct affect it could have on you, today and in the future. I must warn that I consider myself many things, including competent to comprehend most research and convey basic meaning, but I am certainly not an expert in any field, and can therefore make no promises regarding the sagacity or acumen of the content. However, I think you will find this blog not only informative, but interesting - and maybe even a little humorous. I hope you enjoy.